1. Field of the Invention
This invention relates to cleaning brushes and method of use.
More particularly, the present invention pertains to cleaning brushes made of sponge material for use on a machine which cleans discs requiring very precise finishing.
2. Prior Art
Many industries today require the ability to efficiently clean highly finished surfaces, removing particles and other surface contaminants. Specific articles having highly finished surfaces include wafers of semiconductor material, and memory discs.
Semiconductor wafers must be cleaned prior to any processing steps used to produce semiconductor devices. Due to the fragile nature of semiconductor wafers, achieving a high degree of cleanliness, as well as high yield of clean wafers is difficult. Many cleaning devices produce a low yield of clean wafers, due to breakage, or an unacceptable level of surface contaminants.
Memory discs provide less of a problem, being more durable, and requiring, at this time, a lesser degree of cleanliness.
Currently, cleaning devices have been developed to overcome some of these problems. Devices for cleaning wafers generally consist of a cylindrical roller passing over a wafer. The cylindrical roller conventionally includes tufted nylon or other types of bristles extending from a central core. The bristle roller brushes are fixed horizontally and rotated as the wafer or memory disc is passed between the bristle surfaced brushes while the surfaces are copiously drowned in cleaning solution or deionized water.
Wafers cleaned in this manner are often unacceptable due to particles and other surface contaminants missed or passed over in the process. In addition, the softness of the bristles varies according to their composition resulting in a heterogeneous mixture of bristles, each harder or softer than their counterparts. This results in the breakage of the wafers and a loss of circuits, as well as damage to wafer surfaces. Other drawbacks, resulting in unsatisfactory cleaning, may be attributed to the hydrophobic nature of bristle tufted brushes. The fiber surfaces of these brushes are never wetted, and require large amounts of deionized water or cleaning solution to work in the cleaning process.
Memory discs, being more durable in nature and requiring a lesser degree of particle removal, are presently cleaned utilizing a series of mechanical metal wheels each having a plurality of apertures extending therethrough, which receive pieces of hand placed rectangular cubes of porous sponge. Each cube is placed through one of the apertures and manually adjusted by eye to form a nub protruding equidistance from either side of the metal wheel. The manual fabrication technique of these cleaning wheels is long and cumbersome, resulting in increased cleaning costs. Furthermore, these cleaning wheels are inefficient when attempting to clean memory discs. Many times, the final manually constructed brush has overlapping or undersized sponge patterns distributed across its surface due to the difficulties in manually placing the sponge cubes within the apertures of the metal wheels so that the extend equidistance from either surface. The resulting manually fabricated wheels are then gang assembled on a keyway, separated by fixed spacers. Memory discs are then allowed to revolve and rotate between the paired wheels. In this manner both sides of the memory discs are washed simultaneously by the action of the cubic rectangular sponges upon their surfaces.
It would be highly advantageous, therefore to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a cleaning pad for cleaning highly finished surfaces.
Another object of the present invention is to provide a cleaning pad which is relatively inexpensive to produce.
And another object of the present invention is to provide a cleaning pad which may be adapted to a variety of cleaning requirements.
Still another object of the present invention is to provide a cleaning pad which applies a uniform cleaning force to the surface being cleaned.
Yet another object of the present invention is to provide a cleaning pad which allows cleaning fluid to flow freely therethrough.
Yet still another object of the present invention is to provide a cleaning pad which is gentle on the surface being cleaned, substantially eliminating breakage of fragile articles such as semiconductor wafers.
A further object of the present invention is to provide a cleaning pad which is capable of cleaning contours and edges of disc shaped objects due to its three-dimensional shape.
Yet a further object of the present invention is to provide a cleaning pad which is hydrophilic, retaining fluid, and releasing it selectively upon the surface to be cleaned.
And yet a further object of the present invention is to provide a cleaning pad which acts as a pumping and suction cleaning device.